Displays with Local Dimming Elements

Abstract

An electronic device is provided with a display such as a liquid crystal display. The display includes a liquid crystal display module an array of display pixels. A backlight unit is used to provide backlight illumination to the display module. A shutter module having local dimming elements is used to locally control the amount of light that is transmitted through the display. The local dimming elements can be formed from liquid crystal display structures, polymer-dispersed liquid crystal display structures, photovoltaic material, electrowetting display structures, and/or other suitable light controlling elements. Each local dimming element controls the amount of light that is transmitted through an overlapping region of the array of display pixels. The local dimming elements may be arranged in a uniform array having rows and columns or may be shaped and sized differently and located in specific regions of the display.

What is claimed is: 
     
         1 . A display, comprising:
 a display module having an array of display pixels; and   a shutter module having a plurality of local dimming elements, wherein each of the local dimming elements comprises a polymer-dispersed liquid crystal layer and is configured to control the amount of light that is transmitted through at least one of the display pixels.   
     
     
         2 . The display defined in  claim 1  further comprising backlight structures configured to provide backlight illumination to the display module, wherein the shutter module is interposed between the display module and the backlight structures. 
     
     
         3 . The display defined in  claim 1  further comprising backlight structures configured to provide backlight illumination to the display module, wherein the display module is interposed between the shutter module and the backlight structures. 
     
     
         4 . The display defined in  claim 3  wherein each local dimming element comprises photovoltaic material interposed between the polymer-dispersed liquid crystal layer and the display module. 
     
     
         5 . The display defined in  claim 1  wherein the local dimming elements are arranged in an array having rows and columns, wherein the array of local dimming elements has a first resolution and the array of display pixels has a second resolution, and wherein the first resolution is less than the second resolution. 
     
     
         6 . The display defined in  claim 1  wherein the display module comprises a thin-film transistor layer, a color filter layer, and liquid crystal material interposed between the thin-film transistor layer and the color filter layer. 
     
     
         7 . The display defined in  claim 1  further comprising backlight structures configured to provide backlight illumination to the display module, wherein the backlight structures comprise a light guide plate and a light source configured to emit light into an edge of the light guide plate. 
     
     
         8 . The display defined in  claim 1  wherein the local dimming elements comprise a first elongated local dimming element that runs along a first edge of the display and a second elongated local dimming element that runs along a second edge of the display. 
     
     
         9 . The display defined in  claim 1  further comprising a timing controller integrated circuit configured to provide display signals to the display pixels and local dimming signals to the local dimming elements. 
     
     
         10 . The display defined in  claim 9  wherein the display signals and the local dimming signals are synchronized. 
     
     
         11 . The display defined in  claim 1  wherein the display module and the shutter module are laminated together. 
     
     
         12 . A display, comprising:
 at least one display layer having an array of display pixels;   a first local dimming element overlapping a first region of the array of display pixels and configured to control the amount of light transmitted through the first region of the array of display pixels; and   a second local dimming element overlapping a second region of the array of display pixels and configured to control the amount of light transmitted through the second region of the array of display pixels, wherein the first local dimming element and the second local dimming element have different sizes.   
     
     
         13 . The display defined in  claim 12  wherein the first and second local dimming elements each comprise liquid crystal material. 
     
     
         14 . The display defined in  claim 12  wherein the first and second local dimming elements each comprise liquid crystal droplets dispersed in a polymer matrix. 
     
     
         15 . The display defined in  claim 12  wherein the first and second local dimming elements each comprise electrowetting display structures. 
     
     
         16 . The display defined in  claim 12  further comprising a backlight unit configured to provide backlight to the at least one display layer, wherein the first and second local dimming elements are configured to control the amount of backlight that is respectively transmitted through the first and second regions of the array of display pixels. 
     
     
         17 . A display, comprising:
 a liquid crystal display module having an array of display pixels;   a polymer-dispersed liquid crystal display module; and   a backlight unit configured to provide backlight to the array of display pixels.   
     
     
         18 . The display defined in  claim 17  wherein the polymer-dispersed liquid crystal display module comprises an array of local dimming elements, wherein each local dimming element comprises polymer-dispersed liquid crystal material, and wherein each local dimming element is configured to control the amount of light that is transmitted through the polymer-dispersed liquid crystal material associated with that local dimming element. 
     
     
         19 . The display defined in  claim 17  wherein the liquid crystal display module is interposed between the polymer-dispersed liquid crystal display module and the backlight unit. 
     
     
         20 . The display defined in  claim 17  wherein the polymer-dispersed liquid crystal display module is interposed between the liquid crystal display module and the backlight unit.